The crew raised a Mayday alarm with coastguards as the vessel rapidly began to fill with water off Robin Hood's Bay at around 5.15am.

Coastguards ordered the launch of Whitby lifeboat and a search and rescue RAF Sea King helicopter was scrambled from Leconfield. The men - believed to be a father and son - took to their life-raft as the 24m vessel began to sink. They were picked up safe by the lifeboat crew.

Richard Brewer, director of the Anglo-Scottish Fish Producers Organisation and a Whitby skipper, said: "She was a big boat and has always been well looked after.

"Something drastic must have happened very suddenly and she's been overwhelmed and gone down very quickly.

"They have had a very lucky escape indeed because at this time of year the temperature of the sea is very cold and people don't last long in it."

A Humber Coastguard spokesman said: "The two on board took to the life-raft. Several other vessels came to the scene to stand by. The lifeboat crew picked them up and they were OK. We knew from the message it was a Mayday situation."